NORTH OF MEXICO. 317 



The second section of the sub-genns contains those species in which the thorax is 

 strongly constricted at base, almost p idunculate, and the lateral marginal line not attain- 

 ing the basal margin. On account of the extreme variation of which the species arc sus- 

 ceptible, many more names have been applied to the varieties than we can draw lines to 

 separate. On account ol the difficulty of ascertaining accurately the forms to which Esch- 

 scholtz's names were applicable, Dr. Leconte obtained types from Europe, some of which 

 were carefully compared bj the late Dr. Schaum, while others were furnished by Mene- 

 tries and Motschulsky from the original collection of Eschscholtz, and with this assistance 

 and the large numbers of specimens in Dr. Leconte's cabinet and mj own. 1 can safelj as. 

 sort that but three speci< > should he recognized in the fourteen varieties already known to us. 



E. par vicollis, Esch., Zool. Atl. 3, p. 12: Matin. Beitrag. 271: i, Esch . et Mann. loc. •ii 



Mann., loc. cit.; Esch., el Mann. loc. 'it.: Es et Mum.. Ioc. cit.; Proc. 



A. I. 1858, ].. 187. 



This species lias the thorax comparatively smooth. The punctures, though rather 

 coarse, are never confluent, and the thorax has never the scabrous app sarance of tic two 

 succeeding species. Tin elytra are also rather coarsely punctured than intricatelj rugose, 

 as in tin' next. The form of elytra varies greatly, and on this alone have been founded 

 the numerous names cited above a- synonyms. 



/■/. proditcta has the humeral angles very distinct and the disc et' the elytra more tl it- 

 tened, approaching in this respect planipennis. The humeral angles, however, become 

 less distinct, and at the same time the disc more convex, and the transition i-- verj grad- 

 ual and easy through planata and parvicoll is to seabrosa. Typical specimens of all the 

 >]) ;cies are before me. and it is easy to complete series leading gradually from one form to 

 the other, all preserving, however, the common character- given in the synoptic table. 



This species is abundant at San Francisco and around the hay in a southerly direction. 



I .ength . 1:2— .64 inch. 



E. cordata, Esch., Zool. Vtl. 3, p. 10: Mann. Beitr., p. 27::. Esch., et. Mann Ioc. >it.: 



Mann., Beitr., p. 273; rotundip I ■• . ta, Lee, Pacif, I!. K. Reports, App. 1. p. 50. 



Differs from the preceding in having the thorax densely and continently punctured. 

 The sides of the thorax are mere strongly rounded in front, behind the middle nar- 

 rowing rather suddenly, causing them to appear somewhat sub-angulate. This character i> 

 seen in the next spi cies, hot never in the previous one. The elytra are also more rugosi . 

 tin spaces between the punctures are elevated and convex, and more or less confluent 

 transversely. 



The species is abundant in the region of San Francisco, extending its r s i the 

 southward through the Sacramento Valley and into Oregon, where it is replaced by the 

 next species. 



Length .40-.62 inch. 



AMERI. PHILOSO. SOC. — VOL. XIV.— 80 



